Familial aspects of narcolepsy-cataplexy in the Czech Republic.
A group of 153 probands with narcolepsy included 38 subjects (24.8%) with a familial incidence of excessive daytime sleepiness (EDS). In 15 cases (9.8%), at least one additional family member suffered from narcolepsy-cataplexy; only EDS was present in the remaining 23 cases (15.0%). One thousand eighty-two relatives were evaluated. The percentage of first degree relatives affected with narcolepsy-cataplexy was 2.28% (1.20% if only clinically confirmed cases were accounted); the adequate value for second degree relatives was 1.49%. The occurrence of EDS exceeded these values several times (4.28% in first degree relatives, 6.57% in second degree relatives). The vertical mode of transmission was found in most families. Human leukocyte antigen (HLA) typing was performed in six families with multiple-case incidence of narcolepsy. Forty-one blood samples were analyzed (12 patients with narcolepsy, 7 with only EDS, 2 with sleep apnea syndrome, and 20 healthy relatives). HLA DR2+ and DQB1*0602+ were found in only 8 out of 12 narcoleptic patients with cataplexy and in six out of seven patients with isolated attacks of sleepiness. These findings support the hypothesis that there is a common genetic basis for narcolepsy associated with cataplexy and "monosymptomatic" forms of narcolepsy and suggest the existence of non-major histocompatibility complex (MHC) susceptibility factors for narcolepsy.
Nevsímalová
S
S
Department of Neurology 1st Medical Faculty, Charles University, Prague, Czech Republic.
Mignot
E
E
Sonka
K
K
Arrigoni
J L
JL
D000293:Adolescent; D000328:Adult; D002385:Cataplexy / Q000209:etiology / Q000235:genetics* / Q000276:immunology; D018153:Czech Republic; D005260:Female; D005838:Genotype; D006683:HLA-DQ Antigens / Q000276:immunology; D006684:HLA-DR Antigens / Q000276:immunology; D006801:Humans; D018445:Infectious Disease Transmission, Vertical; D008297:Male; D008875:Middle Aged; D009290:Narcolepsy / Q000150:complications / Q000235:genetics* / Q000276:immunology; D010375:Pedigree
D006683:HLA-DQ Antigens; D006684:HLA-DR Antigens